Heat shock proteins (HSP) have shown to be critical to protect against type 1 diabetes mellitus and rheumatoid arthritis, both of which are prevalent chronic degenerative autoimmune diseases.
The criticality was based on the following findings:    1. Peptides of HSP's can be used as therapeutic agents to prevent or arrest the inflammatory damage in both experimental autoimmune arthritis and in experimental autoimmune diabetes. The peptide treatments (in first clinical trials) are marked by a shift in the cytokine profiles of specific autoimmune T cells from a pro-inflammatory Th-1 response to an anti-inflammatory Th-2 response.    2. Epitopes of HSP's are recognised by the adaptive arm of the immune system (antigen receptors of T cells and B cells).    3. Epitopes of HSP's are targets for regulatory T-cells in both diseases.
In models of type I diabetes and arthritis, immunisation with HSP has been seen to prevent and to suppress disease. The probable mechanism here is the expansion of microbial (commensal) HSP reactive T cells, tolerized in the gut through mechanisms of mucosal tolerance. This expansion of HSP reactive T cells was possible through both oral and parenteral routes of HSP administration. The expanded T cells are cross-reactive with homologous self-HSP over-expressed in the inflamed (stressed) tissue. This cross-reactivity of tolerant T cells leads to regulatory cytokine production at the site of inflammation. For type I diabetes and arthritis, first clinical trials in humans have shown the potential of HSP derived peptides from HSP60 and HSP40 to switch cytokine patterns of disease associated T cell specificities into more regulatory cytokine production.
WO95/25744 describes the use of parts of mycobacterial heat shock proteins (HSP65) having mammalian sequence similarity for protection against or treatment of an inflammatory disease, including autoimmune diseases, such as diabetes, arthritic diseases, atherosclerosis, multiple sclerosis, myasthenia gravis, or inflammatory responses due to tumour or transplant rejection. The document only shows data for HSP65-derived epitopes (a HSP60 family member).
U.S. Pat. No. 6,007,821 describes the use of full length, human heat shock proteins HSP90 and HSP70 for the treatment of autoimmune diseases. Only data for using gp96 (a HSP90 member) to treat insulin dependent diabetes mellitus (IDDM) is provided. The effect is seen only after onset of IDDM and the autoimmune response (i.e. the abnormal immune response to self antigens) is said to be reversed by the treatment with full length human gp96. The heat shock proteins used in the therapeutic treatment in U.S. Pat. No. 6,007,821 are preferably obtained from the patients to be treated, i.e. the patient having developed the autoimmune disease (i.e. they are autologous proteins). There is no indication of the use of non-full-length HSP70 or HSP90 proteins and HSP70 peptides are only mentioned in the context of peptides being complexed with full lengths HSP70 protein. Prophylactic treatment is not included in this document. Erroneously, ulcerative colitis is mentioned as being an autoimmune disease.
Kingston et al. (1996, Clin. Exp. Immunology 103: 77) describe that full length recombinant Mycobacterial HSP70 protein can be used to reduce the development of adjuvant arthritis.
Tanaka et al. (1999, J. Immunology 163, 5560-5565) describe that peptide 234-252 of Mycobacterial HSP70 suppresses the development of adjuvant arthritis and induces IL-10 production. Epitope specific T cell lines also have a protective effect. Another peptide (amino acids 84-103) is not effective and does not suppress adjuvant arthritis development. Tanaka et al. suggest that the rat homolog of the Mycobacterial peptide 234-252 may also be suitable for protecting against arthritis, as the T cell line specific for the mycobacterial peptide responded in preliminary trials to the conserved rat peptide (which differs in 8 amino acids from the 19 amino acid long bacterial peptide).
Van Eden (2000, Cell Stress and Chaperones 5: 452-457) provides a review of the protective potential of self-heat shock proteins in arthritis immunization.
Wendling et al. (2000, J. Immunology 164: 2711-2717) tested a panel of overlapping synthetic 15-mer peptides of mycobacterial HSP70 for their ability to induce proliferation of a (full-length) recombinant mycobacterial HSP70-specific T-cell line. Using this approach 4 peptides were identified (amino acids 111-125, 131-145, 397-411 and 490-504). Of these four, peptide 111-125 induced T-cells cross-reactive to the rat homolog of peptide 111-125 (thus to self-HSP70), but parenteral pre-immunization with this mycobacterial peptide did not protect against arthritis development. Nasal administration, on the other hand did result in significant reduction of arthritis.
Dengjel, Schoor et al. (2005, PNAS USA 102: 7922-2927) describe experiments which show that fragments of HSP70 family members are loaded into Major Histo-compatibility Complex class II (MHC class II) molecules when human B cells are cultured under conditions of nutrient deprivation and that this occurs primarily for intracellular cytosolic proteins and not for extracellular proteins. This paper is silent about the use of such HSP fragments for induction of disease suppressive immune regulation.
Crotzer and Blum (2005, PNAS USA 102: 7779-7780) describe the molecular and cell biological basis of the HSP70 uploading of MHC class II and review the evidence that cell stress leads to mechanisms of autophagy and that especially HSP70 family member fragments are loaded into MHC class II molecules by the mechanisms of chaperone mediated autophagy (CMA). There is no mentioning of the possible induction of disease suppressive immune regulation.
Paludan et al. (2005, Science 307: 593-595) describe that lysosomal processing after autophagy contributes to MHC class II-restricted surveillance of long-lived endogenous antigens. In the added supplementary material (Supplemental Table 1) it is described that HSC70 and HSP70 are two of the three most frequent cytosolic/nuclear MHC class II natural ligand sources.
Mizushima, Yamamoto et al. (2004, Mol. Biol. Cell 15: 1101-1111) describe that autophagy is constitutively active and occurs without nutrient deprivation or other cell stress inducing events, in thymic epithelial reticular cells and that such thymic autophagy was more active in newborns. From this one can infer that autophagy contributes to development of T cell repertoire.
Hutszti, Bene et al. (2004, Inflamm. Res. 53: 551-555) describe experiments aimed at supporting the observation that low levels of antibodies against mycobacterial hsp65 are found in patients with IBD.
Elsaghier et al. (1992, Clin. Exp. Immunology 89: 305-309) describe the measurement of antibody levels to mycobacterial and human heat shock proteins in patients with Crohn's disease, ulcerative colitis and non-tuberculous mycobacterial diseases of the lung. They conclude that the data are not sufficient to imply sensitization with mycobacteria in patients with IBD. Thus, other bacterial proteins may be involved in sensitization.
WO 03/072598 describes the use of HSP70 peptides in the diagnosis and treatment of autoimmune disease, in particular type 1 diabetes. Of the diabetes patients tested, most showed proliferative response to eicosapeptides 1-20 (p1), 391-410 (p27) and 511-530 (p35) of the human HSP70. There is no disclosure of the peptides being suitable for use in immune interventions.
WO 2007/054658 discloses the use of certain CD40L and mycobacterial hsp70 sequences for use in the control of immune responses. The hsp70 sequences are the eicosapeptides 407-426, 457-476 and 477-496
There still remains a need for other peptides and compositions suitable for the treatment and/or prevention of IBD and arthritis and/or other autoimmune diseases.
There also remains a need for methods which can be used to identify or select peptides which, when administered in suitable amounts to humans, treat or prevent arthritis and/or other autoimmune diseases or symptoms thereof.
The origin of inflammatory bowel diseases (IBD) is known to depend on the presence of bacterial gut flora and is regarded as an inappropriate hyper-responsiveness to commensal organisms (Bouma and Strober 2003, Nature Rev. Immunol. 3: 521-533). In surgically excluded ileum of Crohn's patients (no fecal stream) lesions were seen to disappear. Infusion of intestinal contents induces recurrent Crohn's disease (D'Haens et al. 1998, Gastroenterology 114:262-267). Moreover, under germ-free conditions no experimental IBD disease can be induced, unless the gut flora is reconstituted (Chandran et al. 2003, Surgeon 1:125-136, Strober et al. 2002, Ann. Rev. Immunol. 20: 495-549). Therefore, supposedly, bacterial antigens are the trigger leading to the induction of disease. In IBD such as Crohn's disease no causally related auto-antigens are known to exist, which is in contrast to auto-immune diseases. IBD are, therefore, considered not to be auto-immune diseases such rheumatoid arthritis is.
Models of IBD have generated evidence for a primary role of anaerobic bacteria (Clostridium, Bacteroides) in the induction of disease (see Verdu et al. 2000, Clin. Exp. Immunol. 120(1):46-50). Crude sonicates of anaerobic, aerobic gram positive and gram negative bacteria have been administered orally in DSS-induced colitis and only sonicates of anaerobic bacteria were found to reduce severity of experimental colitis.